ASP.NET Core application debugging without publishing on IIS

You don't need to run .Net Core in IIS to get easy debugging etc like we used to do as you described.

With .Net Core you can just open a command line at your project root and type "dotnet run"

DotNet Run uses environment variables to drive what it does. So if you want your site to run on a specific URL or port you Type:

SET ASPNETCORE_URLS=http://example.com

Or if you just want it to run on a different port

SET ASPNETCORE_URLS=http://localhost:8080

Then to set the Environment

SET ASPNETCORE_ENVIRONMENT=Development

Once all your environment variables are set, you type

dotnet run

Now to debug it, you attach to cmd.exe with dotnet run in it's Title. You'll be able to debug your code that way.

Now, if you are using Visual Studio There is a file called "launchSettings.JSON" under Properties in your project. You can configure profiles here and I have my default profiles set to Kestrel Development and then Kestrel Production, with IIS dead last so that I don't F5 run in IIS Express.

My LaunchSettings.json looks like this:

{
  "iisSettings": {
    "windowsAuthentication": false,
    "anonymousAuthentication": true,
    "iisExpress": {
      "applicationUrl": "http://localhost:56545/",
      "sslPort": 0
    }
  },
  "profiles": {
    "Kestrel Development": {
      "executablePath": "dotnet run",
      "commandName": "Project",
      "commandLineArgs": "dotnet run",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development",
        "ASPNETCORE_URLS": "http://localhost:8080"
      }
    },
    "Kestrel Production": {
      "commandLineArgs": "dotnet run",
      "commandName": "Project",
      "environmentVariables": {
        "ASPNETCORE_URLS": "http://localhost:8080",
        "ASPNETCORE_ENVIRONMENT": "Production"
      },
      "executablePath": "dotnet"
    },
    "IIS Express": {
      "commandName": "IISExpress",
      "launchBrowser": true,
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    }
  }
}

The first Profile is what F5 uses when you press it. So when I press F5 Visual Studio launches dotnet run for me and set's the Environment and URLS as specified by the environmentVariables section of my profile in launchSettings.JSON.

Now because I have multiple Profiles I get a drop down next to the run button so I can select Kestrel Production if I want to run in Production mode locally.

Follow these steps to be able to achieve what you want.

1. In launchSettings.json, add a property named iis under iisSettings, like so:

   "iis": {
     "applicationUrl": "http://my.aspnetcoreapp.com"
   }
   

2. Under the profiles section, add a new profile having commandName set to IIS. I am calling mine Local IIS. This will add a new option to the Run drop down named Local IIS.

   "Local IIS": {
     "commandName": "IIS",
     "launchBrowser": true,
     "launchUrl": "http://my.aspnetcoreapp.com",
     "environmentVariables": {
       "ASPNETCORE_ENVIRONMENT": "Development"
     }
   }
   

3. Create a website in IIS. Set host name to my.aspnetcoreapp.com. Also create/use an app pool for this website that has .NET CLR version set to "No Managed Code".

4. Set physical path of that website to the location of your asp.net core project, not the solution, unless of course if you have the project in the same folder as the solution.

5. Add a loop back entry in the hosts file (for Windows C:\Windows\System32\drivers\etc\hosts)

   127.0.0.1 my.aspnetcoreapp.com

6. Go back to Visual Studio, and run the application. Make sure you have "Local IIS" profile selected from Run drop-down. This will launch the application in the browser, at the URL, after a brief loading message that says "Provisioning IIS...".

7. Done! From now on, you can launch your application at that URL, and can also debug by attaching to process w3wp.

You could also host your app under "Default Web Site", by specifying the ULR like localhost/MyAspNetCoreApp instead of my.aspnetcoreapp.com. If you do that, a new app pool will be created with the name MyAspNetCoreApp AppPool.

My medium article about this.